[PATCH] i386: Do not align small stack slots to 16 bytes

[Segher Boessenkool]

As Shmuel reported in <https://gcc.gnu.org/ml/gcc-help/2017-03/msg00009.html>,
on x86-64 small structures in automatic storage are aligned to 16 bytes.
This seems to be because of a mix-up between bits and bytes in the i386
target code.

Is this okay for trunk?


Segher


2017-03-06  Segher Boessenkool  <seg...@kernel.crashing.org>

        * gcc/config/i386/i386.c (ix86_local_alignment): Align most aggregates
        of 16 bytes and more to 16 bytes, not those of 16 bits and more.

---
 gcc/config/i386/i386.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 754c016..f03e71a 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -30467,7 +30467,7 @@ ix86_local_alignment (tree exp, machine_mode mode,
                  != TYPE_MAIN_VARIANT (va_list_type_node)))
          && TYPE_SIZE (type)
          && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST
-         && wi::geu_p (TYPE_SIZE (type), 16)
+         && wi::geu_p (TYPE_SIZE (type), 128)
          && align < 128)
        return 128;
     }
-- 
1.9.3